The present invention relates to a thermal shield structure with ceramics for wall surfaces which are exposed to high temperatures, and more particularly to an arrangement for supporting ceramic blocks to such wall surfaces.
In a device having a wall surface which is exposed to high temperatures, for example, in a liner of a combustor of a gas turbine, for protecting the wall surface from high temperatures to retain its mechanical strength, it has been proposed to cover the wall surface of the liner with ceramic blocks. For mounting the ceramic blocks, it is general practice to form wedge-shaped support grooves on the wall surface of the liner in its axial direction and fit in the grooves wedge-shaped support projections provided on the ceramic blocks. In practice, however, it often happens that some of the wedge-shaped support projections cannot be fitted into the grooves and, even if fitted into the grooves, there exist large amounts of play. Accordingly, it is necessary to select from a number of ceramic blocks those which can be fitted into the grooves with a small amount of play; therefore, assembling of the ceramic blocks is very cumbersome. Further, since the thermal expansion coefficients of the metal forming the liner and the ceramic blocks are different, even if the support projections of the ceramic blocks are snugly fitted into the support grooves, it is very likely that during heating, play is introduced in the assembly by the thermal expansion of the liner which is larger than the thermal expansion of the ceramics.